WASHINGTON (CNN) - Frances Lewine, who covered the White House for the Associated Press during the administrations of six presidents and spent nearly three decades as a CNN assignment editor and field producer, died Saturday of an apparent stroke. She was 86.

Lewine was regarded as a trailblazer who battled for women's rights in journalism, fighting to open the National Press Club and the Gridiron Club - a Washington journalists' organization - to women.

"It's amazing that at her age, Fran was still staking out administration and elected officials after weekend talk shows," CNN Washington Bureau Chief David Bohrman said. "All of journalism has lost a true pioneer."